automatic picture transmission station

automatic picture transmission station, in meteorology, any of several hundred installations, located in most of the countries of the world, that can receive and display the weather-forecasting data that is continuously transmitted by orbiting artificial satellites launched by the United States. The information gathered by the sensing equipment in the satellites is received in the form of facsimile visible and infrared pictures of cloud formations, snow and ice cover, and the sea surface, from which weather conditions can be inferred. The system began operation in the mid-1960s, employing the Tiros series of Earth satellites.

Improvements in the sensing equipment carried by the satellites have made it possible for the stations to receive information concerning the temperatures of the surface and the cloud tops and the temperature variation within the atmosphere at intervals up to 50 kilometres (31 miles). The temperature data have been found useful in extending the time interval for which reliable predictions of the weather can be made.